Grain dryer chamber



June 7, 1966 w. s. AUSHERMAN 3,254,430

GRAIN DRYER CHAMBER Filed May 9, 1962 2 Sheets-Sheet 1 iiiiii iill liliiiiiii i ifiiiiiiii FIG. 2 242 ZIO INVENTOR. 16 L WILLIAM s. AUSHERMAN FIG. 54/

ATTORNEY June 7, 1966 w. s. AUSHERMAN GRAIN DRYER CHAMBER 2 Sheets-Sheet 2 Filed May 9, 1962 FIG. 4

FIG. 5

INVENTOR.

WILLIAM S. AUSHERMAN ATTORNEY United States Patent 3,254,430 GRAIN DRYER CHAMBER William S. Aushermau, 3500 N. Topeka, Wichita, Kans. Filed May 9, 1962, Ser. No. 193,428 8 Claims. (Cl. 34-174) This invention relates to new and useful improvements in grain dryers, and more particularly pertains to improvements increasing the versatility of a grain dryer as to the character of the materials that can be dried thereby, and to improvements affording better control of the rate at which grain is processed therethrough and which minimizes the bridging and consequently the channeling of heated air through the material being dried as caused by trash and other foreign matter contained in the material being dried.

A primary object of the instant invention is to provide a grain dryer that can eificiently dry a large quantity of material in a given length of time, and which will accomplish such drying economically from the standpoint of the' amount of water removed in relation to the amount of fuel consumed.

Another primary object of the invention is to provide a grain dryer of the type wherein grain passing between a pair of screens is dried by the transverse movement of heated air therethrough such that the spacing of the screens is adjustable to accommodate the dryer to most effectively dry any given material under various conditions of moisture content, and also to accommodate the dryer to processing materials widely difiering as to size, flow characteristics, etc.

Still another primary object of the invention is to provide a grain dryer such that the rate of travel of all portions of the grain passing therethrough can be uniformly regulated, and such that the deleterious and wastefiul effects of voids being formed in the material passing through the grain dryer as occasioned by foreign matter bridging between the screens can beveliminated or substantially avoided.

Other objects, features and advantages of the grain dryer of this invention will hereinafter become apparent.

' Broadly, the invention relates to a grain dryer of the class wherein a chamber for heated air is partially defined by a vertically inclined outer screen with an inner screen being disposed in the chamber in spaced and generally parallel relation to the outer screen, a grain bin being disposed above the screens and arranged to discharge into the space between the screens, and with means being provided for supplying heated air in the chamber. One broad aspect of the invention has to do with the provision of a trough disposed in spaced relation below the inner screen and having an edge secured to the bottom edge of the outer screen, with a flow rate controller comprising a shaft disposed in spaced parallel relation in the trough. The shaft is mounted for rotation and is provided with a plurality of circumferentially spaced, radially extending vanes extending along the length of the outer screen, with such vanes being of a radial extent to terminate adjacent the trough and the lower edge of the inner screen with free running clearance.

Another broad aspect of the invention has to do with a grain dryer of the class wherein a chamber for heated air is partially defined by a pair of spaced walls and a vertically inclined outer screen extending between the spaced walls, with an inner screen being disposed in the chamber in spaced and generally parallel relation to the outer screen, a grain bin being disposed to discharge into the space between the screens, and means being provided for supplying heated air in the chamber, such class of grain dryer embodying the improvement of the inner screen extending between and slidingly abutting the spaced ucts such as corn, sorghums, peanuts, wheat, oats, barley,

3,254,430 Patented June 7, 1966 ice , outer screens can be varied, together with the provision of means for securing the inner screen at a plurality of selected positions of differing spacing from the outer screen.

Another broad aspect of the invention involves a grain dryer of the class hereinbefore specfied that incorporates either one or both or neither of the improvements specified in the two immediately preceding paragraphs, such class of grain dryers being provided with an agitator for facilitating the discharge of grain from the bin into the space between the screens in a manner that tends to avoid trash in the grain from bridging between the screens and causing voids in the grain, such agitator being disposed adjacent the top of the screens and comprising a generally horizontal shaft mounted for rotation adjacent the top of the screens, with the agitator shaft having grain agitating means for an intermediate portion of its longitudinal extent, and being provided at its opposite end portions with oppositely twisted angers. Still another aspect of the invention involves an improved grain dryer of the class previously defined, wherein there are two sets of outer and inner screens provided, with each of such sets of screens being provided with a trough connected to the outer screen and a flow rate controller associated therewith, the inner edges of the troughs being connected to a generally V-shaped bottom wall for the chamber, and with an auger or equivalent conveyor means disposed in the chamber adjacent the apex region of the V-shaped bottom wall whereby grain can be moved from the heated air chamber.

A final important aspect of the invention to be specifically enumerated herein involves a grain dryer of the class previously defined incorporating the improvements set forth in the preceding paragraph which additionally involves the provision of an auger or equivalent conveyor means for moving grain from the previously mentioned auger or conveyor to the bin, such conveyor means for moving grain to the bin being provided with means for selectivity diverting grain from passing into the bin into some other receptacle such as an adjacent granary or transport vehicle. This version of the invention can optionally be provided with an auxiliary feed auger or equivalent conveyor means that is detaehably coupled to the juncture of the previously mentioned conveyor means for moving grain from a feed point (such as a hopper into which grain can be scooped, or the outlet of a granary or some other transport mechanism) to the intake of the conveyor means for moving grain into the bin.

As used in this specification and the appended claims, the word grain is not to be strictly construed as meaning only grain such as wheat or flax, or coarse grains such as oats and barley, but rather is to be interpreted as being generic to a wide variety of agricultural prodrye, etc. Usually the agricultural products to be dried are shelled or threshold prior to drying though this is not necessarily always the ease as, for example, in the case of peanuts. Although the principal purpose of the grain dryer is for the drying of agricultural products, it will be evident that its use is not necessarily limited to agricultural products and can be employed in the drying of other materials such as substances pelleted by a wet process, etc.

The invention will be best understood and other objects, features, and advantages of the same will be readily appreciated in the light of the following description of a preferred embodiment of the invention illustrated in the accompanying drawings, wherein:

FIGURE 1 is a side elevational view of the grain dryer of the invention, with the prime mover and a 3 hopper for the auxiliary feed auger being shown in dashed outline;

FIGURE 2 is a front elevational view of the grain dryer shown in FIGURE 1 with the wheeled undercarriage of the same being removed;

FIGURE 3 is a rear elevational view of the structure shown in FIGURE 2, with the auxiliary feed auger removed;

FIGURE 4 is an enlarged transverse vertical sectional view taken upon the plane of the section line 4-4 in FIGURE 1;

FIGURE 5 is a reduced elevational view of the agitator; and,

FIGURE 6 is an enlarged isometric detail view of the structure enabling adjustable spacing of the inner screen with respect to the outer screen.

Referring now to the drawings wherein like reference numerals designate like parts throughout the various views, the reference numeral 10 designates the grain dryer generally. The dryer 10 includes a frame comprised of side rails 12 and 14 connected at their front and rear ends by cross members 16 and 18. The frame elements 12 through 18 inclusive are preferably rigidly connected together as by welding or the like. The frame 12 is supported upon a wheeled carriage comprised of wheels 20 and 22 mounted on an axle 24 that is secured to the side rails 12 and 14 in any suitable manner. The provision of a more elaborate wheeled carriage (multi-axle type if deemed necessary or expedient) such as may include a spring suspension system is deemed well within the skill of the art.

The frame also includes as fixed components thereof a pair of front support columns 26 and 28 and a pair of rear support columns 30 and 32. The upper ends of the support columns 26 and 28 are connected by a frame member 34 and the upper ends of the support columns 30 and 32 are connected by a frame member 36, while the upper ends of the pairs of columns 26 and 32, and 28 and 30 are respectively connected by frame members 38 and 40. For a reason subsequently to become apparent, the frame members 34 through 40 inclusive constitute a rectangular frame or bed for detachably supporting a rectangular set of side walls constituting an upper bin extension designated generally at 42.

A spaced pair of horizontal frame members 44 and 46 are connected between the support columns 26 and 28, and a corresponding pair of horizontal frame members 48 and 50 are connected between the support columns 30 and 32. A front wall 52 is secured to the rearmost sides of the frame members 24, 34', 44 and 46, and a rear wall 54 is secured to the foremost sides of the frame members 18, 36, 48 and 50. A central support 56 for the bottom wall of a bin subsequently to be described extends longitudinally of the dryer 10 between the front and rear walls 52 and 54 with its opposite ends respectively secured through such walls to the frame members 34 and 36. A pair of bin supports 58 and 60 and a further pair of bin supports 62 and 64 are provided with each of such bin support members 58-64 extending between the front wall 52 and the rear wall 54 of the dryer 10, and with each of such members being suitably secured through such front and rear walls 52 and 54 to the frame members 46 and 50 by means not shown.

A bin structure is provided having a bottom Wall formed of four sections each of which extends between the front and rear walls 52 and 54, such bottom wall for the bin structure being comprised of a section 66 that is inclined and having its upper and lower edges respectively secured to the frame member 40 and the support member 56. The second section of the bottom wall for the bin structure is designated at 68 and is inclined oppositely to the bottom wall section 66 and has its upper and lower edges respectively supported by the support members 56 and 60. The reference numeral 70 designates a further section of the bottom wall for the bin structure and the same is inclined vertically with its upper and lower edge portions being secured to the support members 56 and 62 respectively, and the fourth and final section of the bottom wall for the bin structure is designated at 72, such wall section 72 being inclined opposite to that of the section 70 and having its upper and lower edges secured respectively to the frame member 38 and the support member 64.

As clearly shown in FIGURE 4, the adjacent lower edges of the bottom wall sections 66 and 68 are spaced apart uniformly throughout their horizontal extent between the front and rear walls 52 and 54. Similarly, the adjacent lower edges of the bottom wall sections 70 and 72 are spaced apart uniformly throughout their horizontal extent between the front and rear walls 52 and 54.

As thus far described, it will be seen that the bottom wall sections 66, 68, 70 and 72 along with the front and rear walls 52 and 54 in conjunction with the bin extension 42 constitutes a bin construction having right and left hand portions 74 and 76 respectively that each discharge through longitudinally elongated discharge openings or slots defined respectively by the adjacent edges of the bottom wall sections 70 and 72 for the bin portion 74 and the adjacent edges of the bottom wall sections 66 and 68 of the bin portion 76.

A pair of outer screens 78 and 80 respectively fixed in rectangular frames 82 and 84 are provided, with the frames 82 and 84 being secured to and extending between the front and rear walls 52 and 54 in an arrangement such that the screens 78 and 80 are inclined vertically, and are preferably vertical as shown. For reasons of structural strength, it is preferred that the frames be releasably secured by means of nuts and bolts (not shown) to the frame members 44, 46, 48 and 51). The upper edges of the frames 82 and 84 terminate respectively beneath the lower edge portions of the wall sections 66 and 72 and are preferably secured to such bottom wall sections. A pair of troughs 86 and 88 extend between the front and rear walls 52 and 54 and have their outer or opposite edges secured to the lowermost edges of the frames 82 and 84, as shown. The inner or adjacent edges of the troughs 86 and 88 are joined by a heated air chamber bottom wall 98 of generally V-shape that extends between the front and rear *walls 52 and 54, it being noted that the inner or adjacent edges of the troughs 86 and 88 are of lesser vertical height than are the outer edges of the troughs 86 and 88. As thus far described, it will be seen that a chamber for heated air 92 is defined by the bottom wall sections 68 and 70 of the bin construction, the screens 78 and 80, the troughs 86 and 88, the V-shapcd bottom wall 90, and the front and rear walls 52 and 54.

A pair of inner screens 94 and 96 carried respectively in rectangular frames 98 and 188 are provided with the inner screen 94 being disposed in parallel spaced relation to the screen 7 8 and the screen 96 being disposed in spaced parallel relation to the screen 80. The screen frames 98 and 101} slidingly abut the front and rear walls 52 and 54 so as to be movable towards and away from their respective screens '78 and 80. Means is provided in relation to each of the frames 98 and 189 for retaining the same in adjusted spaced relation with respect to their associated screens 78 and 80. Since the securing means for the frames 98 and are identical, only those provided in association with the screen frame 98 are described in detail.

The securing means for the frame 98 are best shown in FIGURES 4 and 6, wherein it will be seen that a plurality of horizontally spaced openings 102 are provided through the front wall 52 adjacent the upper edge of the frame 98, it being understood that a corresponding set of openings (not shown) is provided through the rear wall 54 adjacent the top edge of the frame 98. A nut and bolt 104 extend through the frame 98 and a selected one of the openings 102 so as to secure the upper edge of the frame 98 in adjusting the spaced relation to the upper edge of the screen 78. In a similar manner, a nut and bolt (not shown) secure the rear upper edge of the frame 98 in adjusted spaced relation to the upper rear portion of the screen 7 8.

In an analogous fashion, a series of horizontally spaced openings 106 are provided in the front wall 52 adjacent the lower edge of the frame 98 and a nut and bolt 108.

extends through the frame 98 in a selected one of the openings 106 to secure the lower portion of the frame 98 in adjusted spaced relation from the screen 78. It is to be understood that analogous means (not shown) are provided adjacent the lower rear portion of the frame 98 for securing the frame 98 to the rear :wall 54 in adjusted spaced relation to the screen 78. For reasons of structural strength, the openings 102 and 106 extend through the frame members 46 and 44 so that the nuts and bolts 104 and 108 extend through the frame members 46 and 44. Corresponding mounting provision is made at the other end of the frame 98. Once the frames 98 and 100 are secured in adjusted relationship to their respective screens 78 and 80, the unused openings 102 and 106 are pluggedin any suitable manner such as by nuts and bolts secured therethrough (not shown). On inspection of FIGURE 4, it will be seen that the inner screens 94 and 96 are disposed below the bottom wall sections 68 and 70 of the bin portions 76 and 74, so that grain discharged from the bin portions 76 and 74 respectively passes between the outer and inner screens 78 and 94, and 88 and 96 for any adjusted positions of the inner screens 94 and 96. Preferably, the range of adjustment of the inner screen frames 98 and 100 is such that the spacing of the screens 78 and 94, and 80 and 96 ranges in discrete steps from about one inch to about six inches for the purpose of drying agricultural products such as wheat, barley, oats, shelled corn, and rye. With a full scale working embodiment of the illustrated form of the invention it has been found that excellent results in the drying of wheat has been obtained when the spacing of the inner and outer screens has been about three inches, though greater and lesser spacings would be preferred when the dryer is employed to dry wheat that is initially dryer or wetterz,

Closable access openings (not shown) are provided in the front and rear walls 52 and 54 at positions affording communication with the interior of the heated air chamber 92 adjacent the top and bottoms of the screen frames 98 and 100 through which access can be had to the nuts and bolts 104 and 108 whereby adjustment of the frames 98 and 100 with respect to the screens 78 and 80 can be conveniently effected. Such closable access openings can be provided with glass or other transparent closures (not shown) by means of which the operator of the dryer 10 can view the interior of the chamber 92 during operation of the dryer 10, such as during adjustment of the means for supplying heated air to the chamber 92 subsequently to be described.

Means is provided adjacent the upper ends of 'the outer and inner screens 78 and 94 in conjunction with the bin portion 76 in order to insure the proper feeding of grain from the bin portion 76 into the space between the screens 78 and 94. Such means are designated generally at 110, with analogous means 112 being provided in conjunction with the inner and outer screens 96 and 80 in relation to the bin portion 74. Since the means 110 and 112 are analogous to each other, a detailed description of the means 110 will suffice for both. The agitator means 110 comprises a shaft 114 journaled through the front and rear walls 52 and 54 for rotation, such shaft 114 being disposed between the lower adjacent portions of the bottom wall sections 66 and 68 and above the space intervening between the outer and inner screens 78 and 94. An intermediate portion of the longitudinal extent of the shaft 114 between the front and rear walls 52 and 54 is provided with a plurality of staggered radial fingers 116 of such length as to have the extremities thereof pass with free-running clearance closely adjacent to the bottom Wall sections 66 and 68 as Well as in fairly close proximity to the upper edges of the screens 78 and 94. The shaft 114 diameter suitable for free-running clearance.

is provided (see FIGURE 5) with oppositely twisted augers 118 and 120. The auger 118 extends from the intermediate portion of the shaft 114 provided with the fingers or projections 116 to a position closely adjacent to the front wall 52, while the auger 120 extends from the intermediate portion of the shaft 114 provided with the fingers or projections 116 to a position spaced closely adjacent to the rear wall 54.

The twist of the augers 118 and 120 is such that during rotation of the shaft 114 the augers 118 and 120 tend to move grain with which they are in contact toward the intermediate portion of the shaft 114 provided with the fingers or projections 116 from the extremities of the' shaft 114.

The function of the projections or fingers 116 is to agitate and break up any such consolidations or caking of grain as may occur within the bin so as to insure free and uninterrupted smooth fiow of grain into the space between the outer and inner screens 78 and 94. While projections or fingers 116 can be extended along the entire length of the shaft 114 between the front and rear walls 52 and 54, the provision of the oppositely twisted augers 118 and 120 along such portions of the shaft 114 that are adjacent the front and rear walls 52 and 54 is preferred for the reason that such augers 118 and 120 not only serve to agitate and break up any caking of grain in their vicinity, but such augers 118 and 120 are much preferred for the reason that trash and foreign matter passing from the bin portion 76 tends to be distributed by the augers 118 and 120 in such a manner that such trash and'foreign matter has a far lesser likelihood of concentrating and bridging between the outer and inner screens '78 and 94 so as to obstruct the flow of grain between the screens 78 and 94. The reason that the augers 118 and 120 are disposed adjacent the front and rear ends of the bin portion 76 is for the reason that as grain passes from a bin and the surface thereof becomes lowered the trash and foreign matter contained within the grain tends to move to the peripheral or terminal portions of the bin, and consequently, the problems presented by the presence of such trash or foreign matter (as for example, twigs, grass, leaves,-etc.) are much more aggravated adjacent the front and rear walls 52 and 54 of the bin portion 76. Though not so shown, the helical edges of the augers 118 and 120 can be provided with spaced short projections or fingers radially extending therefrom to further aid in the agitation of the grain and the distribution of trash and foreign matter so that the deleterious effects of the latter can be minimized. In any event, it is preferred that the radial extent of the augers 118 and 120 have a Obviously, when the augers 118 and 120 are provided with fingers or projections (not shown), the overall diameter of the augers and the projections is such as to afford ample freerunning clearance. Means will be described presently for driving the agitator means 110 and 112.

Identical means is provided in connection with each of the sets of inner and outer screens 94 and 78, and 96 and for regulating and making the flow rate uniform throughout the horizontal longitudinal extent of such screens, such means being designated generally at 122 and 124 respectively. Inasmuch as the flow rate controlling means 122and 124 are identical, a detailed description of the flow rate control means 122 will suflice for both. The flow rate control means 122 comprises a shaft 126 disposed within or concentric with the trough 86, such shaft 126 being journaled in the front and rear walls 52 and 54 of the dryer 10 for rotation. The shaft 126 is disposed at a position approximately directly below the lower edge of the inner screen 94 throughout the range of horizontal adjustability of the screen 94, and the shaft 126 is provided throughout its longitudinal extent between the front and rear walls 52 and 54 with a plurality of circumferentially spaced radially extending 'vanes 128. The vanes 128 preferably extend straight along the length of the shaft 126 (though a slight helical twist to the vanes 128 is not to be excluded, especially when the direction of twist is alternately reversed along the length of the shaft 126) and have a radial extent such as to pass closely adjacent to the inner surface of the trough 86 and the lower edge of the screen frame 98 with free-running clearance. As seen in FIGURE 4, counterclockwise rotation of the shaft 126 of the flow rate controller 122 results in essentially all of the grain passing downwardly between the screens 78 and 94 passing between the shaft 126 and the trough 86, with a negligible amount, if any, of the grain passing into the lower portion of the chamber 92 between the screen frame 98 and the shaft 126. With the illustrated and described structure, it will be seen that the rate at which grain is allowed to flow from the space between the screens 78 and 94 is a function of the geometry of the flow rate controller 122 and the trough 86 and the rate at which the shaft 126 is rotated. Not only is the flow rate of the grain controlled, but it will also be observed that the illustrated and described construction makes for the rate of grain flow to be essentially uniform throughout the horizontal extent of the screens 78 and 94. Driving means for imparting equal rates of rotation to the flow rate controllers 122 and 124 will be presently described.

Grain passing through the troughs 86 and 88 at rates dependent upon the speed of rotation of the flow rate controllers 122 and 124 descends to the lowermost portion of the chamber 92 defined by the apex region of the V-shaped bottom wall 90. Conveyor means is disposedadjacent the bottom of the chamber 92 for moving grain from within the latter to a conveyor outside the chamber 92. Though such conveyor means can take other forms such as an endless belt conveyor (not shown) for example, the preferred embodiment of the invention incorporates such conveyor means in the form of auger means. Accordingly, disposed along the bottom of the chamber 92 adjacent the apex of the bottom wall 90 is an auger 130 fixed on a shaft 132. The auger 130 is rotated in such a direction as to urge grain in the bottom of the chamber 92 toward the rear of the chamber 92 and into the lower end of a vertical auger housing 134 with such auger being secured to a shaft 138 such that the same is rotated in a direction to move grain introduced in the lower end of the housing 134 about a vertical axis, whereby grain discharged from the chute 140 can be directed into selected portions of the bin of the grain dryer or directed into a grain truck or the like parked adjacent to the grain dryer 10. The lower portion of the auger housing 134 is fixedly secured to the grain dryer 10 by brackets 144 and 146, while the upper end portion of the housing 134 designated at 148 is detachably coupled at 150 so that the auger housing portion 148 as well as the chute 140 and swivel 142 can be removed so as to lessen the overall height of the grain dryer 10 when the same is being moved from one location to another, it being noted that means (not shown) of conventional character are provided for detachably coupling such portion of the rotatable component of the auger disposed within the housing 148.

To conveniently enable inspection of the grain within the bin of the grain dryer 10 and'also to enable convenient manipulation of the swivel 142 and the discharge chute 140 carried thereby, a lower portion 154 of a ladder is fixedly secured to the rear end of the grain dryer at a position adjacent the auger housing 134. The ladder also includes an upper portion 156 that is detachably coupled to the lower portion 154 of the ladder at positions indicated at 158. As thus far described, it will be seen that the overall vertical height of the grain dryer 10 can be considerably lessened from that shown so as to meet with highway regulations and to enable passing under low objects. Such lessening of the overall height of the grain dryer 10 involves removal of the grain bin portion 148 of the auger housing 134, and detachment of the upper portion 156 of the ladder.

An auxiliary conveyor means is provided that preferably takes the form of a feed auger 160 detachably connected to the grain dryer 10, whereby grain can be fed from a hopper such as that indicated in dashed outline at 162 into the lower input end of the auger housing 134. The auxiliary feed auger 160 includes a housing 164 that is detachably coupled at 166 to a tubular element 168 communicating with the interior of the auger housing 134. The auger 160 includes a rotating component 170 that is driven from a gear box 172 that is mounted on the auger housing 164. The means for driving the gear box 172 will be presently described.

A tubular fan housing 176 is mounted on the front wall 52 about an opening 178 in the latter, and a fan 180 is fixed to a shaft 182 that is journaled in a spider 184 attached to the fan housing 176. A fuel burner 186 is attached to the fan housing 176 and has communication with the interior of the latter for discharging heated combustion products into the fan housing 176 at a position disposed forwardly of the fan 180. The burner 186 is of any conventional type suitable for burning propane or butane, or heavier hydrocarbons such as gasoline, kerosene and diesel fuels, the fuel being supplied to the burner 186 by a fuel line 188 connected to a source of supply (not shown).

The means for driving the fan 180, the agitators 110 and 112, the flow regulators 122 and 124, the auger 130, the auger contained within the housing 134, and the gear box 172 for the auger 170 will now be described. A main driven shaft designated at 190 is mounted by means not shown upon the forward end of the dryer 10, such shaft 190 being adapted by any suitable means to be driven for rotation about a horizontal axis extending longitudinally of the dryer 10 by the power takeoff of a tractor or any other prime mover, or to be driven by an internal combustion engine such as that indicated in dashed outline at 192 mounted upon a rigid portion of the frame 193 of the dryer 10, as shown. A belt 194 is entrained over pulleys 196 and 198 respectively fixed to the shafts 190 and 182 whereby the fan 180 is driven, it being noted that the burner 186 is intermediate the pulley 198 and the fan 180.

An elongated shaft 200 is mounted for rotation and extends along one side of the dryer 10 as best shown in FIGURE 1. The shaft 200 is directly driven from the shaft 190 by a drive that includes a belt 202 entrained over a pulley (not shown) fixed on the shaft 190 and a pulley 204 fixed on the shaft 200. A stub shaft 206 is directly driven from the shaft 200 by means of a belt 208 entrained over a pulley 210 fixed on the shaft 200 and a pulley 212 fixed on the shaft 206. A pulley 214 is fixed on the shaft 126 of the flow regulator 122, and a pulley 216 is fixed on the corresponding shaft of the flow regulator 124. A pair of pulleys 218 and 220 are fixed to the stub shaft 206, and a twisted belt 222 is entrained over the pulleys 216 and 220, and a belt 224 is entrained over the pulleys 214 and 218 in an arrangement such that the pulley 216 is driven in a counterclockwise direction from the shaft 206 while the pulley 214 is driven in a clockwise direction from the shaft 206 as seen in FIGURE 2. The bearing journal 226 for the shaft 206 is mounted in such a manner as to enable vertical and horizontal adjustment of the position of the shaft 206, whereby the tension on the belts 208, 222 and 224 can be conveniently adjusted. The arrangement comprises the bearing journal 226 being mounted on a bar 228 that can be secured in a horizontally adjusted position by means of an adjustable clamp or fastener 230 that extends through a horizontal slot 232 in the bar 228. The end of the bar 228 remote from the slot 232 is vertically adjustable by means of an adjustable clamp or fastener 234 carried by the bar 228 that projects through a vertical slot 236 pro- 9 vided in a bracket 238 fixed to the dryer 10. With the arrangement described the clamps 230 and 234 can be loosened and the bar 228 shifted horizontally and vertically to position the shaft 206 as desired and the clamping members 230 and 234 then tightened to retain the shaft 206 in adjusted position.

The auger shaft 138 is driven by means of a pulley 240 fixed to the shaft 200 adjacent the rear end of the grain dryer 10 and a pulley 242 fixed to the shaft 138 as best shown in FIGURE 3. A drive belt 244 is entrained over the pulleys 240 and 242 and over a pair of idler guide pulleys 246 and 248 carried by the frame of the grain dryer 10. The arrangement of the idler pulleys 246 and 248 is such that the pulley 242 is driven about a vertical axis while the pulley 240 rotates about a horizontal axis. The auger 130 is also driven from the shaft 200 by an arrangement that comprises a pulley 250 fixed to the shaft 132 of the auger 130 and a pulley 252 fixed to the shaft 200. A twisted drive belt 254 is entrained over the pulleys 250 and 252 so as to drive the shaft 132 and the auger 130 carried thereby.

The means for rotating the agitating means 110 and 112 comprises the shaft of the agitator means 112 being provided with a pulley 260 at the rear end of the grain dryer 10, and a drive belt 262 is entrained over the pulley 260 and a pulley 264 fixed to the shaft 200. A drive belt 266 is entrained over pulleys, not shown, fixed to the shafts of the agitator means 110 and 112, so that the agitator means 110 and 112 rotate in unison. As shown in FIGURE 3, the pulley on the shaft 114 over which the belt 266 is entrained is concealed by a guard 268 fixed to the dryer 10 for the safety of persons using the ladder A stub shaft 270 is journaled to the dryer 10 at a position adjacent the lower end of the auger housing 134, and the stub shaft 270 is driven by means of a belt 272 entrained over pulleys 274 and 276 respectively fixed to the shafts 200 and 279. A drive shaft 278 is drivingly coupled to the gear box 172 and is detachably coupled by a conventional shaft coupler means 280 to the stub shaft 270, whereby the gear box 172 is driven in such a manner that rotation is imparted to the auger 170 of the auger 160. The shaft coupler means 280 can include a universal joint to compensate for any misalignment of the shaft 278. As described, it will be seen that the auxiliary feed auger 160 as well as the drive means therefor are detachably coupled by means of the couplings 166 and 280 so that the same can be removed from the balance of the grain dryer 10 so as to reduce the overall length of the same when it is desired to move the grain dryer 10 from one location to another.

As best shown in FIGURES 1 and 2, a trailer or tow hitch 282 is rigidly connected to the frame 193 by a tow frame 284, whereby the dryer 10 can be readily coupled to the tow hitch of a towing vehicle for moving the same from one location to another. It is not essential, of course, that the dryer 10 be provided with a wheeled carriage and a trailer hitch unless portability is desired. The grain dryer 10 is of such utility and function that the same can be built as a permanent installation to form a component part of a grain elevator storage system for continuous operation in drying and recirculating the grain stored in the elevator system.

From the foregoing it will be seen that there has been provided a grain dryer construction of unusual flexibility and utility that is of simple and economic design. Of particular advantage is the simple though effective means provided for enabling adjustment of the spacing of the inner screens with respect to the outer screens, whereby the length of the travel path of heated gases through the grain between the inner and outer screens can be adjusted to meet any particular set of drying conditions, it being understood that in the operation of the grain dryer 10 that external air is heated by the burner 186 and driven into the chamber 92 by the fan 180, with the heated air 10 within the chamber 92 thence passing out from the chamber 92 through the grain disposed between the sets of screens 78 and 98, and 96 and 80. During the passage of the heated air through the grain disposed between the screens the grain is heated and moisture driven therefrom by the air passing through the same.

Of special importance is the fact that the illustrated agitator means 110 and 112 coupled with the flow regulators 122 and 124 permits the screens to be spaced closely adjacent each other so that it is not essential that the air temperature within the chamber 92 be of very high temperature and still be capable of driving moisture from the grain disposed within the screens without substantial condensation of previously evaporated water on the grain close to the outer screens 78 and 80. The advantage of the use of the illustrated and described agitator means 110 and 112 in avoiding the deleterious effects of the pressure of trash and foreign matter in the grain has been previously set forth. The advantages of the illus-. trated and described flow rate controllers 122 and 124 have also been given previously.

The frame members of the grain dryer are preferably constructed of angle iron wtih permanently attached portions thereof being welded together. The front and rear walls 52 and 54, the bin bottom wall sections 66 through 72 inclusive, and the sheet'metal portions of the bin extension 42 are preferably made of galvanized iron so as to be resistant to corrosion and are of sufficient thickness as to impart sufficient strength and rigidity to the overall structure. The screens 78, 94, 96 and 80 are of a strength and mesh suitable to perform the desired functions thereof. Preferably, the screens are made of or coated with a metal resistant to corrosion and have as large openings therein as will prevent the passage of the grain therethrough. Preferably, the screen frames 82, 98, 100 and 184 are detachably mounted and removable through the previously described access openings, whereby they can be removed and replaced as may be necessitated by wear or the need for substituting screens of different mesh size. The illustrated and described preferred embodiment of the invention is obviously susceptible to numerous variations and modifications without departing from the spirit of the invention, and accordingly, reference must be made to the appended claims in order to determine the actual scope of the invention.

I claim: 1. In a grain dryer of the class wherein a chamber for heated air is partially defined by a vertically inclined outer screen with an inner screen being disposed in the chamber in spaced and generally parallel relation to 'the outer screen, a grain bin disposed above the screens and arranged to discharge into the space between the screens, and means for supplying heated air in the chamber; the combination therewith of an agitator for facilitating the discharge of grain from the bin into the space between the screens in a manner that tends to avoid trash in the grain from bridging between screens and causing voids in the grain, said agitator being disposed adjacent the top of the screens and comprising a generally horizontal shaft mounted for rotation adjacent the top of the screens, said agitator shaft being provided with grain agitating means for an intermediate portion of its longitudinal extent, and said agitator shaft having its opposite end portions provided with oppositely twisted angers.

2. In a grain dryer of the class wherein a chamber for heated air is partially defined by a pair of spaced walls and a vertically inclined outer screen extending between the spaced walls, with an inner screen being disposed in the chamber in spaced and generally parallel relation to the outer screen, a grain bin is disposed to discharge into the space between the screens, and means is provided for supplying heated air in the chamber; the combination therewith of said inner screen extending between and slidingly abutting the spaced walls for sliding movement toward and away from the outer screen whereby to vary the spacing of the inner and outer screens, means for securing the inner screen at a plurality of selected positions of differing spacings from the inner wall, an agitator for facilitating the discharge of grain from the bin into the space between the screens in a manner that tends to avoid trash in the grain from bridging between screens and causing voids in the grain, said agitator being disposed adjacent the top of the screens and comprising a generally horizontal shaft mounted for rotation adjacent the top of the screens, said agitator shaft being provided with grain agitating means for an intermediate portion of its longitudinal extent, and said agitator shaft having its opposite end portions provided with oppositely twisted angers.

3. In a grain dryer of the class wherein a chamber for heated air is partially defined by a vertically inclined outer screen with an inner screen being disposed in the chamber in spaced and generally parallel relation to the outer screen, a grain bin is disposed above the screens and arranged to discharge into the space between the screens, and means is provided for supplying heated air in the chamber; the combination therewith of a trough disposed in spaced relation below the inner screen and having an edge secured to the bottom edge of the outer screen, a flow rate controller comprising a shaft disposed in spaced parallel relation in the trough, said shaft being mounted for rotation and being provided with a plurality of circumferentially spaced, radially extending vanes extending along the length of the outer screen, said vanes being of a radial extent to terminate adjacent the trough and the lower edge of the inner screen with free running clearance, an agitator for facilitating the discharge of grain from the bin into the space between the screens in a manner that tends to avoid trash in the grain from bridging between screens and causing voids in the grain, said agitator being disposed adjacent the top of the screens and comprising a generally horizontal shaft mounted for rotation adjacent the top of the screens, said agitator shaft being provided with grain agitating means for an intermediate portion of its longitudinal extent, and said agitator shaft having its opposite end portions provided with oppositely twisted augers.

4. In a grain dryer of the class wherein a chamber for heated air is partially defined by a pair of opposed, vertically inclined outer screens with a pair of inner screens being disposed in the chamber in spaced and generally parallel relation to each of the outer screens respectively to constitute two sets of spaced screens, a grain bin is disposed above the chamber and arranged to discharge into the spaces defined by the two sets of spaced screens, and means is provided for supplying heated air in the chamber; the combination therewith of a pair of troughs respectively disposed in spaced relation below the inner screens, a generally V-shaped bottom wall for the chamber, each of said troughs having an outer edge secured to the lower edge of the outer screen adjacent thereto and an inner edge attached to an adjacent edge of the bottom wall, an anger in the chamber and extending along the apex portion of the bottom wall for discharging grain from the chamber, a pair of flow rate controllers respectively associated with the pair of troughs, each controller comprising a shaft rotatably mounted in one of the troughs with such shaft being provided with a plurality of circumferentially spaced, radially extending vanes along the length thereof that terminate radially to afford free running clearance from the associated trough and inner screen, and a pair of agitators associated with each set of outer and inner screens for facilitating the discharge of grain from the bin into the spaces between the outer and inner screens in a manner that tends to avoid trash in the grain from bridging between the outer and inner screens and causing voids in the grain, the agitator associated with each set of outer and inner screens being disposed adjacent the top of such screens and comprising a generally horizontal 5. In a grain dryer of the class wherein a chamber for heated air is partially defined by a pair of opposed, vertically inclined outer screens with a pair of inner screens being disposed in the chamber in spaced and generally parallel relation to each of the outer screens respectively to constitute two sets of spaced screens, a grain bin is disposed above the chamber and arranged to discharge into the spaces defined by the two sets of spaced screens, and means is provided for supplying heated air in the chamber; the combination therewith of a pair of troughs having U-shaped bottoms respectively disposed in spaced relation below the inner screens, a generally V-shaped bottom wall for the chamber, each of said troughs having an upstanding outer edge secured to the lower edge of the outer screen adjacent thereto and an inner edge attached to an adjacent edge of the bottom wall, an auger in the chamber and extending along the apex portion of the bottom wall for discharging grain from the chamber, and a pair of flow rate controllers respectively associated with the pair of troughs and being generally respectively concentric with the U-shaped bottoms thereof, each controller comprising a shaft rotatably mounted in one of the troughs with such shaft being provided with a plurality of circumferentially spaced, radially extending vanes along the length thereof that terminate radially to afford free running clearance from the associated trough and inner screen, wherein the chamber is additionally defined by a pair of opposed walls connected by the outer screens, said inner screens slidingly abutting the opposed walls for sliding movement toward and away from their respective outer screens, means carried by and extending through the walls for securing each of the inner screens at a plurality of selected positions of differing spacing from its respective outer screen, and a pair of agitators associated with each set of outer and inner screens for facilitating the discharge of grain from the bin into the spaces between the outer and inner screens in a manner that tends to avoid trash in the grain from bridging between the outer and inner screens and causing voids in the grain, the agitator associated with each set of outer and inner screens being disposed adjacent the top of such screens and comprising a generally horizontal shaft mounted for rotation adjacent the top of the screens, said agitator shaft being provided with grain agitating means for an intermediate portion of its longitudinal extent, and said agitator shaft having its opposite end portions provided with oppositely twisted augers.

6. In a grain dryer of the class wherein a chamber for heated air is partially defined by a pair of opposed, vertically inclined outer screens with a pair of inner screens being disposed in the chamber in spaced and generally parallel relation to each of the outer screens respectively to constitute two sets of spaced screens, a grain bin is disposed above the chamber and arranged to discharge into the spaces defined by the two sets of spaced screens, and means is provided for supplying heated air in the chamber; the combination therewith of a pair of troughs respectively disposed in spaced relation below the inner screens, a generally V-shaped bottom wall for the chamber, each of said troughs having an outer edge secured to the lower edge of the outer screen adjacent thereto and an inner edge attached to an adjacent edge of the bottom wall, an anger in the chamber and extending along the apex portion of the bottom wall for discharging grain from the chamber, a pair of flow rate controllers respectively associated with the pair of troughs, each controller comprising a shaft rotatably mounted in one of the troughs with such shaft being provided with a plurality of circumferentially spaced, radially extending vanes along the length thereof that terminate radially to afford free running clearance from the associated trough and inner screen, and a second auger disposed outside the chamber and having its input end arranged to receive grain from the first-mentioned auger, said second auger having its discharge end disposed adjacent the top of the bin, a discharge chute swiveled to the second auger for selectively directing grain discharged therefrom into the bin and adapted to discharge into another receptacle, and a third auger, said third auger being disposed outside the chamber and having its discharge end arranged to feed into the inlet of the second auger, with the inlet of the third auger being adapted to receive grain from a hopper.

7. The combination of claim 6, including a pair of agitators associated with each set of outer and inner screens for facilitating the discharge of grain .from the bin into the spaces between the outer and inner screens in a man-' ner that tends to avoid trash in the grain from bridging between the outer and innerscreens and causing voids in the grain, the agitator associated with each set'of outer and inner screens being disposed adjacent the top of such 20 screens and comprising a generally horizontal shaft mounted for rotation adjacent the top of the screens, said agitator shaft being provided with grain agitating means for an intermediate portion of its longitudinal extent, and

References Cited by the Examiner UNITED STATES PATENTS 2,627,670 2/ 1953' Hurst 34-174 2,706,345 4/1955 Arndt 34174 3,000,107 9/ 1961 Ryan 34-174 3,053,522 9/ 1962 Applegate 34-174 3,090,133 5/1963 Kline et al 34-174 FOREIGN PATENTS 10/1928 Germany.

5/1904 Great Britain.

said agitator shaft having its opposite end portions pro- 25 W. C. EVERETT, J. J. CAMBY, Assistant Examiners.

vided with oppositely twisted augers. 

1. IN A GRAIN DRIVER OF THE CLASS WHEREIN A CHAMBER FOR HEATED AIR IS PARTIALLY DEFINED BY A VERTICALLY INCLINED OUTER SCREEN WITH AN INNER SCREEN BEING DISPOSED IN THE CHAMBER IN SPACED AND GENERALLY PARALLEL RELATION OT HE OUTER SCREEN, A GRAIN BIN DISPOSED ABOVE THE SCREENS AND ARRANGED TO DISCHARGE INTO THE SPACE BETWEEN THE SCREENS, AND MEANS FOR SUPPLYING HEATED AIR IN THE CHAMBER; THE COMBINATION THEREWITH OF AN AGITATOR FOR FACILITATING THE DISCHARGE OF GRAIN FROM THE BIN INTO THE SPACE BETWEEN THE SCREENS IN A MANNER THAT TENDS TO AVOID TRASH IN THE GRAIN FROM BRIDGING BETWEEN SCREENS AND CAUSING VOIDS IN THE GRAIN, SAID AGITATOR BEING DISPOSED ADJACENT THE TOP OF THE SCREENS AND COMPRISING A GENERALLY HORIZONTAL SHAFT MOUNTED FOR ROTATION ADJACENT THE TOP OF THE SCREENS, SAID AGITATOR SHAFTS BEING PROVIDED WITH GRAIN AGITATING MEANS 